2000 starts, idles, runs, but breaks down and sputters when getting on the throttle

[LEDBiker]

I have this bike for a few years. Worked great, then the old TPS started acting up and I started getting flat spots when getting on the throttle. It would stumble at low RPM but as soon as the flat spot was passed it would pull like freight train up to red line.

Messed around with adjusting the TPS in dealer mode. -C00 but the flat spot would never go away, just move around.

So I replaced the TPS. Since then, my problems have gotten worse.

First thing, putting the bike in dealer mode and adjusting the TPS does nothing. The indicator is stuck at _C00 and will not move no matter which direction I rotate the TPS. It worked like poop, it was the end of the season so I just put it away and rode another bike.

This year I went back at it. Problem is worse and feels like fuel starvation issues. I took apart the entire fuel system, cleaned the tank, tank sock, replaced the filter in the external pump as well as the two screens. New plugs, cleaned and oiled the air filter. It wasn't as dirty as I've seen many but happy to be clean. Checked all the hoses and vacuum lines. Everything seems to be fine.

Still works like crap. Starts easy, idles fine, and will rev just fine with no load. As soon as I get it on the road it stumbles at low RPM and will stumble every time I get on and off the throttle. If I hold the throttle at say 1/3 it will stumble for a second, and then climb smooth to about 8000r rpm where it starts to break down again.

Remember the damn TPS and how it was acting. Tried to set it up again. Will not move the indicator from _C00. It won't move running when I move the throttle either.

Could I have a dead/malfunctioning TPS out of the box? I can't think of what else could be causing it. Because I left it so long without chasing it down I am out of warranty for the TPS which sucks but I have no problem buying a new one if that is what my problem is.

Is there another way I can test it to see if it is buggered? Anyone else have any suggestions?

 

[LEDBiker]

I forgot to add a photo which obviously makes the entire thread worthwhile, rather than worthless

Also, the bike does start easily and idles well. 1-2 seconds turning over and it starts right up even cold.

 

[Bumblebee]

I forgot to add a photo which obviously makes the entire thread worthwhile, rather than worthless

Also, the bike does start easily and idles well. 1-2 seconds turning over and it starts right up even cold.

View attachment 1654561

View attachment 1654562

Good looking bike, wish I could do something to help but you seem to have everything done I would have suggested...

 

[LEDBiker]

Thanks. I wish you could too!

I feel like the "new" TPS was worse than my old "dead" one. I should have kept it to compare or swap back. I really don't want to spend $200 on a new one and find it it was something else.

 

[Bumblebee]

Thanks. I wish you could too!

I feel like the "new" TPS was worse than my old "dead" one. I should have kept it to compare or swap back. I really don't want to spend $200 on a new one and find it it was something else.

Hopefully @Kiwi Rider is along shortly, he knows these things inside and out...there are a few others who have their pencils sharpened when it comes to gen 1s as well....

The collective will help you soon with any luck...that's too beautiful of a bike to be sitting...

 

[LEDBiker]

I've tried to check the voltage on the TPS. I inserted wires into the back of the connector so I could get a reading (yellow and black wires) and all I get for voltage is .503 DC no matter what way I turn the throttle when the key is on. Not sure if I did this right but that's what I got out of.

I did discover another problem, not sure if it would be related. I have the tank opened with the fuel lines connected and there must be a crack in the hose on the feed side as its streaming out fuel when the tank is up. It wasn't leaking yesterday when it wasn't opened as far so I am guessing the crack widened as I lifted the tank higher and now the fuel is spewing out. I'll be replacing that right away.

Not sure if that could have been sucking in air or spewing fuel out but I'm sure its not helping and I don't want my bike to burn up so....

 

[Bumblebee]

I've tried to check the voltage on the TPS. I inserted wires into the back of the connector so I could get a reading (yellow and black wires) and all I get for voltage is .503 DC no matter what way I turn the throttle when the key is on. Not sure if I did this right but that's what I got out of.

I did discover another problem, not sure if it would be related. I have the tank opened with the fuel lines connected and there must be a crack in the hose on the feed side as its streaming out fuel when the tank is up. It wasn't leaking yesterday when it wasn't opened as far so I am guessing the crack widened as I lifted the tank higher and now the fuel is spewing out. I'll be replacing that right away.

Not sure if that could have been sucking in air or spewing fuel out but I'm sure its not helping and I don't want my bike to burn up so....

That could very well contribute to the issue as it could cause a slight fuel starvation problem?

 

[LEDBiker]

I had a piece of high pressure 5/8 fuel line so I cut it, put the spring on it and got it up and running.

It runs worse!

I feel like my lines aren't routed correctly or getting pinched off so I took a drive with the tank propped up with the seat removed and it ran 10x better. Started stumbling over 7K and cut out a few times but it worked better up than down so that might be part of the problem as well.

Trouble is I am not sure how or where the problem is. Everything looks like its in the right place but once the tank closes completely I can't be sure.